Defining Initiating Events

Initiating Events copied from the Consequence’s associated HAZOP, will show here. These will be indicated with an.

If applicable you can create more Initiating Events or change the existing ones (the changes will be synced back to the HAZOP).

The Initiating Event Frequencies and the Barrier PFDs that you defined, will be used to calculate the SIL levels for the Consequence Categories. This can then be used to assess if the adequacy of the LOPA’s defined Barriers and if a SIF is needed.

Creating and defining Initiation Events

To create and define an Initiating Event:

• To add an Initiating Event, click the + Add Initiating Event button, or click one of the arrow buttons to add an Initiating Event before or after the selected card. Note: If connected to a HAZOP, you will be asked to specify the HAZOP Node and Deviation where the associated Cause should be added.
  If connected to a HAZOP, specify where the Cause should be added. 
• Click the fold-out bar to open the Initiating Event Properties.
  Click the fold-out bar. 
• To use already defined failure rates from the IMS database, click From Existing to use an Initiating Event already used in another LOPA, or click From Template to create an Initiating Event from a template.
• A popup will open. Search for and select the appropriate Exiting Initiating Event or Template Initiating Event. Note: If you add an Exiting Initiating Event a copy will be created, i.e., Initiating Events will not be shared between LOPAs.
• Review the properties:
  • For the Existing, you can review the Frequency Low and Frequency High. You can also use the LOPA hyperlinks to navigate to the associated LOPAs where the Initiating Event is being used; or
  • For the Template, you can review the Frequencies per year and select a Template.
• Click OK (or Cancel) to close the popup.
• Change the Enabling factor, if needed. This will influence the Demand Rate/Year (DR), since the Initiating Event’s Frequency is multiplied by this factor. The default is 1.
• Add a Description.
• Search for and select an Associated Equipment for Initiating Event if applicable.
• When done, click X to close the fold-out.

It is also possible to not use a Template or an Existing Initiating Event. In this case you should edit the card description and the Frequency as well:

• To edit the Initiating Event’s description, just click on the card (i.e., select the card) and start typing.
  To edit the description, just click on the card (i.e., select the card) and start typing.

  
  

• Click in the L and H section of the Frequency to change the values. Note: If you are not defining Frequency as a range, enter the same value in both L and H fields.

Adding/Deleting Initiating Events

Use the Toolbar or Shortcut keys to Add / Delete Initiating Events.